Sifting device



Nov. 3, 1936. E. SCHNEIDER ET Al. 2,059,814

SIFTING DEVICE Filed Feb. 23, 1955 2 sheets-sheet 1 NOV. 3, 1936. E;l SCHNEHDER ET AL 2,059,814

SIFTING DEVICE Filed Feb. 25, 1935 2 Sheets-Sheet 2 Fig- 2.

Patented Nov.. 3, 1936 UNITED 'iriS OFFIQE the-Rhine, Germany,

assignors to Bttner- Werke Aktiengesellschaft, Uerdingen, Germany Application February 23, 1935, Serial No. 7,737

lin Germany February 23, 1934 v 8 Claims.

Applications for patents have been made in Germany No. B164,444 filed 23rd February 1934 and No. B166,528 i'lled 15th August 1934.

This invention relates to sifting devices for separating solid material from air or waste gases and particularly from gases emanating from drying equipment. Ordinarily such equipment requires a relatively high escape pipe for the gas with the result that the separator is normally located below the upper end of the pipe.

One of the principal objects of the invention is to provide a sifting device in which the gas connections aid materially in the separation of solid particles, particularly heavy particles. A further object of the invention is to provide a sifting device in which the solid particles are substantially separated in the piping system and are delivered into the gas entering a separator chamber in an advantageous manner to insure the grading or classication of the separated solids.

Other objects, advantages and capabilities of the invention will appear from the following description of two preferred embodiments thereof taken in conjunction with the accompanying drawings in which:

Figure 1 is a diagrammatic elevational view showing one embodiment of the invention, and Fig. 2 is a diagrammatic elevational view showing another embodiment of the invention.

Referring to Figure 1 of the drawings, a designates the riser which receives gas from the pneumatic drier. This riser normally has to be quite high and it is connected at its upper end to a return bend member b, which in turn is connected to an elbow c. This elbow delivers into a separating chamber d. This separator is a gravity separator in which the solid material falls out of the gases, the gases more or less freed from solids passing off through the conduit shown on the left in Figure 1. A vertical slide e located near this outlet enables the degree of iineness of the precipitated material to be controlled to some extent.

It will readily be understood that the gases flowing rapidly upwardly through a are diverted by the return bend b and that as a result of this sudden bend, the solid contents of the gas are thrown outwardly around the outer wall of the return bend member b. The plate f is mounted on the outer wall of the return bend member b in such a manner that the solid material may impinge against it. The plate f may be adjusted at will so that a greater or smaller amount of the solid material may be diverted thereby into (Ci. 18S- 80) 2 pipe g. The pipe y isprovided with an air lock h and delivers into the 'elbow c in a vertical direction at a point where the gases passing through the elbow c are entering into the separating chamber d. This delivery of the solid materials into th-e current of gases enables the latter to carry the solid materials into the separating chamber d in a free falling condition, which is remarkably advantageous for classifying the solid material, that is to enable the heavier materials to deposit and enable the lighter solid materials to be carried away. It is to be noted that the air lock h removes substantially all the kinetic energy from the solid material and gases passing through the pipe g so that the solid materials are not in a rapidly moving condition, but are presented to the incoming gases in a free falling condition so that they are classied or graded in an advantageous manner by the main stream of gases which is moving transversely or horizontally.

It will readily be understood that the gases passing through the elbow c are very largely denuded of solid materials. If desired, a bypass may be provided whereby a certain amount of the gases passing through the elbow c may be carried directly to the outlet conduit without passing through the chamber d. Thus we may provide a conduit i which has an inlet lc connected to the elbow c and an outlet m connected to the outlet pipe The conduit i may contain a valve n so that the amount of gases diverted through the by-pass may be controlled at will.

The control of the gases passing through the by-pass exercises a corresponding change in the amount of gases passing from the elbow c into the chamber d and thus the classifying eiiect may be adjusted at will by merely manipulating the valve n.

In the embodiment of .the invention shown in Fig. 2, the riser a is connected to the return bend b as in the previously described embodiment. This return bend is connected to a pipe g. At the lower end of the pipe g is an air lock h whereby solidmaterial may be supplied directly from the pipe g into the separating chamber d. A delecting plate f is pivotally mounted on the inner side of the pipe g, that is the side adjacent the pipe u, and remote from the path of the descending solid material which moves along the outer surface of the inverted U structure, owing to centrifugal force. The deiiecting plate f deiiects a large amount of the gases, which is substantially free from solid material, into the pipe c which Supplies the gases into the settling Icontaining the coarser particles vfrom chamber d. It will readily be seen from Fig. 2 that the incoming gases pass transversely or horizontally below the solid material which enters the chamber d through the air lock h. It may here be noted that as mentioned in connection with the previously described embodiment, the incoming solid material has no velocity, but falls freely under the iniluence of gravity with the result that it is classified or graded by the transverse flow of gases supplied by the pipe c. The chamber d is substantially similar to that of the previous embodiment and a by-pass icoontrolled by the valve n enables a certain amount of the gases to be by-passed so .that the grading can be controlled as heretoforedescribedin connection with the previously described embodiment.

Having thus described our inventionpwe declare that what we claim isz- 1. A chamber-gravity separator for pneumatic drying devices, comprising a drying conduit, a deflecting bend portion connected to the upper end thereof, a separator connected to said bend and means for deecting the-coarser particles as they pass aro-und said bend and to deliver them uppermost upon the air or gas stream as it enters said separator, said means including a scraper plate, a conduit for conducting the air or gas said scraper plate to the upper part of the separator adjacent its connection with the deecting bend portion, an air-lock between said conduitV and the separator for destroying the kinetic energy of the particles before they'are delivered to the separator, and a conduit for delivering the remaining part of the air or gas current from the deflecting bend portion to the separator below said first-mentioned conduit.

2. A chamber-gravity separator for pneumatic drying devices, comprising a-drying conduit, a deecting bend portion connected to theV upper end thereof, a separator connected to said bend and means for deflecting the coarser particles as they pass around said bend andto deliver them uppermost upon the air or gas stream as it enters said separator, said `means including a scraper plate, a conduit for conducting theair or gas containing the coarser particles from said scraper plate to the upper part of Vthe separator adjacent its connection with the defiecting bend portion, an air-lock between said conduit and the separator for destroyingV the kineticenergy of the particles before they are delivered to the separator, and a conduit for delivering the remaining part of the air or gascurrent from' the deflecting bend portion to the separator below said rst-mentioned conduit, and means for transferring any excess quantity of air" or gas past the separator.

3. A sifting device comprising a rising conduit, a deflecting bend in said conduit, achambergravity separatorv provided with la controlling valve, a substantially vertical second conduit connecting said bend with said separator, an airlock interposed between said second'conduit and aid separator, a scraping plate in said second conduit, and a third conduit by-passmg sala scraping plate, a portion of said second conduit and the air-lock and connecting with said separator.

4. A sifting device according to claim 3, including a fourth conduit by-passing said separator and connecting with said third conduit, and a valve in said fourth conduit.

5. A separating device for pneumatic driers,

. comprising an elongated conduit, a return bend member connected to the upper end thereof, a gravity-chamber, a conduit connecting said return bend member to said chamber and adapted to project gases thereinto in a horizontal direction, means for withdrawing solid material separated from the gases by movement around the return bend, means for arresting said solid material and supplying it to the chamber in free falling relation to the incoming gases.

6. A device for removing solids from gases from drying systems, comprising an elongated riser, a return bend connected thereto, a conduit connected to said return bend and adapted to discharge gas supplied to said riser in a horizontal direction, a gravity separator chamber connected to the outlet of last said conduit, another conduit adapted to receive solid material separated from the gases by movement around the return bend, an air lock for removing the inertia of said solid material and delivering it into the horizontal stream of gases entering the gravity separator.

'7. A separating device for pneumatic driers, comprising an elongated conduit, a return bend member connected to the upper end thereof, a gravity-chamber, a conduit connecting said return bend member to said chamber and adapted to project gases thereinto in a horizontal direction, means for withdrawing solid material separated from the gases by movement around the return bend, means for arresting said solid material, supplying it' to the chamber in free falling relation to the incoming gases, and a controllable by-pass in parallel with the separating chamber whereby the now of gases through the chamber can be regulated to regulate the classifying or precipitating effect thereof.

8. A device for removing solids from gases from drying systems, comprising an elongated riser, a return bend connected thereto, a conduit connected to said return bend and adapted to discharge gas supplied to said riser in a horizontal direction, a gravity separator chamber connected to the outlet of last said conduit, another conduit adapted to receive solid material separated from the gases by movement around the return bend, an air lock for removing the inertia of said solid material, delivering it into the horizontal stream of gases entering the gravity separator, and a controllable by-pass in parallel with the separating chamber whereby the flow of gases through the chamber can be regulated to regulate the classifying or precipitating effect thereof.

ERNST SCHNEIDER. KARL BLUM. 

